JPH1173621A - Laminated thin film disk for longitudinal recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a multilayered magnetic layer exhibiting single switching operation with a smooth hysteresis loop by depositing a multilayered magnetic layer of two or more layers with crystalline orientation PO[1010] with min. changes in the coercive force Hc of each magnetic layer. SOLUTION: A seed layer 12 having B2 structural material, a nonmagnetic base layer 13 such as chromium and chromium alloy, a magnetic layer 14, a spacer layer 15, a magnetic layer 16 and a coating film 17 are sequentially deposited on a substrate 11. The seed layer 12 and the base layer 13 are required to enhance PO[1010] in the magnetic layers 14, 16. The magnetic layers 14, 16 consist of a cobalt alloy containing platinum and chromium and contain additional elements such as tantalum and boron, and for example, CoPtCrTa or CoPtCrB. Thereby, the two-layer multilayered magnetic film comprising the magnetic layers 14, 16 does not exhibit a two-mode switching effect, so that irregularity in the hysteresis loop can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the field of data storage devices such as disk drives having thin film magnetic disks. Specifically, the present invention relates to a thin-film magnetic disk having a plurality of magnetic layers.

[0002]

2. Description of the Related Art A magnetic recording disk in a conventional drive assembly generally includes a substrate, a base layer made of a thin film of chromium (Cr) or a Cr alloy, and a cobalt-based magnetic alloy layer deposited on the base layer. A protective coating layer on the magnetic layer. Various disk substrates, such as NiP coated AlMg, glass, glass-ceramic, glass-carbon, have been used. The microstructure parameters of the magnetic layer, namely crystal orientation (PO), grain size, and magnetic exchange decoupling between grains play an important role in controlling the recording characteristics of the disk. The Cr base layer is used primarily to control microstructural parameters such as PO and grain size of the cobalt-based magnetic alloy. The PO of the various materials that form the layers on the disk is not necessarily the exclusive orientation found in that material, but is merely the primary orientation. When a Cr-based layer is deposited at high temperature on a NiP-coated AlMg substrate, a [100] oriented (PO) is usually formed. This PO is [1120] P
Promotes the epitaxial growth of the hcp cobalt (Co) alloy of O, thereby improving the magnetic performance in the plane of the disk. [1120] PO refers to a film with a hexagonal structure whose (1120) plane is almost parallel to the surface of the film.
Similarly, [1010] PO refers to a film having a hexagonal structure whose (1010) plane is almost parallel to the surface of the film.
Cr or Cr on glass and most nonmetallic substrates
Because the nucleation and growth of the alloy base layer is significantly different from their nucleation and growth on NiP-coated AlMg substrates, media fabricated on glass substrates are formed on NiP-coated AlMg substrates under the same deposition conditions. Noise is often greater than that of a medium that has been lost. This is why it is necessary to use an initial layer (called a seed layer) on the substrate.
A seed layer is formed between the replacement substrate and the substrate to control nucleation and growth of the substrate, and the substrate affects the magnetic layer. Al, Cr, C on glass and non-precious metal substrates
rNi, Ti, Ni ₃ P, MgO, Ta, C, W, Z
Several materials, such as r, AIN, NiAl, have been proposed as seed layers. (For example, "S
eed Layer induced (002) crystallographic texture i
n NiAl underlayers ", J. Appl, Phys. 79 (8), 1996.4
See March 15, p.4902ff. ) For a single magnetic layer disc,
Laughlin et al. Describe a method of using a 2.5 nm thick Cr base layer and a CoCrPt magnetic layer after using a NiAl seed layer. A NiAl seed layer with a Cr base layer was said to incorporate a [1010] texture in the magnetic layer. ("The Control and
Characterization of the Crystallographic Textureof
Longitudinal Thin Film Recording Media '', IEEE Tr
ans. Magnetic. 32 (5), September 1996, 3632.)

The signal-to-noise ratio (SN) of a thin-film disk medium
Improvement in R) is still one of the major issues in high-density recording technology. Various techniques have been proposed for reducing the medium noise, such as selecting a low-noise alloy, designing an appropriate base layer, adjusting the adhesion parameter, and laminating the magnetic layer. The laminated disk has two or more magnetic layers separated by a spacer layer. For example, Ahlert et al. In commonly assigned U.S. Pat.
Mg / NiP substrate and 6 layers of CoPtX alloy or CoNiX separated by Cr, CrV and Mo layers
A laminated disk having a layer of an alloy is described.

It is known that lamination of magnetic layers of a thin-film disk reduces medium noise. However, in a laminated medium, generally, the coercivity (Hc) of each stacked magnetic layer may be largely different. Therefore, a two-mode switching action is shown. Laminated media with optimal performance need only exhibit one type of switching action. this is,
This means that the stacked magnetic layers must have very similar Hc. For most magnetic alloys used in thin film disk technology, Hc is a function of deposition temperature. That is, Hc increases with the substrate temperature. A sputtering system used for mass production of magnetic disks has a function of preheating a substrate, but the temperature of the substrate decreases as the progress of the sputtering process elapses. Thus, when sputtering a laminated magnetic layer on a preheated substrate, the second layer is deposited at a lower temperature and generally has a lower Hc. A decrease in Hc of the second layer contributes to a deviation (kink) in the smooth slope of the hysteresis loop, at least near the zero remanence state. FIG.
(A) and FIG. 3 (b) show a single magnetic layer (Cr
/ CoPtCrTa) and a two-layer laminated magnetic film (Cr / CoP)
4 shows a typical hysteresis loop of (tCrTa / Cr / CoPtCrTa). The kink of hysteresis of the laminated film is clearly seen. The existence of this kink indicates that this membrane is 2
It has two switching characteristics,
As a result, the recording performance of the disc in high-density recording decreases. Therefore, in order to eliminate or minimize this kink,
It is desirable to design a laminated medium without switching action.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a thin-film disk having a laminated magnetic layer that exhibits a single switching operation resulting in a smooth hysteresis loop.

[0006]

SUMMARY OF THE INVENTION The design of a thin film disk with a laminated magnetic layer for use in a disk drive will be described. The disc reduces noise and exhibits a single switching effect, resulting in improved recording performance in disc drives using the disc. This improved disc has a Pc with minimal change in Hc.
It is formed by attaching two or more laminated magnetic layers having O [1010]. In one embodiment, [101
[0] The PO magnetic layer is formed by adhering a B2 structure seed layer such as NiAl or FeAl and an appropriate base layer having [112] PO. Disks using the present invention have a smooth hysteresis loop with minimal signs of two-mode switching. The seed layer is Ni
Preferably, the base layer is Cr or a Cr alloy. The magnetic layer is made of CoPtCr, Co
PtCrTa or CoPtCrB is preferred. The spacer layer between the magnetic layers is preferably made of the same material as the base layer, but may be a different material such as a hexagonal crystal material such as Ru. The disc according to the present invention has [1]
[010] The ease of manufacturing in a standard high volume sputtering system is high because it appears that the Hc of the magnetic layer with PO is less dependent on the substrate temperature.

[0007]

FIG. 1 is a top view of a prior art disk drive with a rotary actuator useful in practicing the present invention. The system includes one or more magnetic recording disks 111 mounted on a spindle 112 that is rotated by an in-hub electric motor (not shown). Actuator assembly 11
5 supports a slider 120 that includes one or more read / write heads. The assembly comprises a plurality of actuators and sliders arranged in a vertical stack, the actuators supporting a slider in contact with the surface of the disk and not contacting when the disk is not spinning and when retracting. To do. A voice coil motor (VCM) 116 swings the actuator assembly 115 about the shaft 117, thereby moving the assembly 115 with respect to the disk. The head is typically
It is contained within an air bearing slider that is adapted to fly above the surface of the disk when spinning at sufficient speed. In operation, as the slider flies above the disk, the VCM moves the slider into an arcuate path across the disk, causing the slider to move magnetically from an annular track formed in a thin-film coated data area 114, which will be described in more detail below. The head can be arranged to read and write information. The electrical signals exchanged between the head and the VCM are transmitted by flexible cable 118 to drive electronics 119. When not operating or during periods when the disk starts or stops, the slider is moved to the landing zone or contact start / stop (C
SS) region 113 so as to physically contact the disk surface. The CSS area 113 is not used for data storage even though the magnetic coating extends over that area. It is also known to use a retract ramp to remove the slider from the disk during non-operation. Although a disk drive with an air bearing slider has been described, the disk of the present invention can be readily used with other storage devices having a proximity or contact recording slider.

FIG. 2 shows a sectional layer structure of an embodiment of the thin-film magnetic disk according to the present invention. A thin film layer is deposited on at least one side, preferably both sides, of the disc to form a data storage area. Shading is only used to distinguish each layer and does not indicate color or a particular composition.
Substrate 11 can be AlMg / NiP, glass, or any other suitable material. In one embodiment, the seed layer 12 is a B2 structural material directly attached to the substrate, and is preferably NiAl. Base layer 13
Is deposited on the seed layer and is chromium or CrV
And a non-ferromagnetic material such as a chromium alloy such as CrTi. A requirement of the seed layer and the base layer of the disk according to the present invention is to enhance [1010] PO in the magnetic layer. The first ferromagnetic layer 14 (Mag1) is typically an alloy of cobalt with platinum and chromium, and may include additional elements such as tantalum and boron, for example CoPtCrTa or CoPtCrB. A typical magnetic layer comprises 4-14 atomic percent platinum and 18-23 atomic percent.
Atomic% chromium and 1-5 atomic% tantalum,
The rest is Co. The spacer layer 15 is made of a non-ferromagnetic material and can optionally be of the same material as the base layer.
The second ferromagnetic layer 16 (Mag2) is preferably made of the same material as Mag1. At least two magnetic layers separated by non-magnetic spacers are required, but additional spacer / magnetic layer pairs can be added. The optional top layer is a protective coating 17, which may be carbon, hydrogenated carbon, or any other protective material. Also,
It is also known in the art to use additional layers between the magnetic layer and the cover layer to enhance the adhesion of the cover layer and increase the hardness. These various layers are preferably sputter deposited using standard techniques, targets, temperatures, and pressures well known to those skilled in the art. Although the present invention relates to laminated magnetic layers, the deposition techniques and parameters are the same as those used in single magnetic layer discs using comparable materials.

FIG. 5 is a flow chart showing the steps of one method of making a disk according to the present invention. All layers from the seed layer to the cover layer can be sputtered in an in-line sputtering system or in a continuous process in a single disk system.
Current commercial in-line sputtering systems are:
Additional targets and multiple pass paths can be provided to make the laminated disk structure. Designing an inline system with additional targets is a straightforward task.
Single disk systems with six or more target capacities to produce a stacked disk structure are also commercially available. As shown in FIG. 5, each layer is sequentially sputter deposited, starting with a substrate that can be AlMg / NiP, glass, or other suitable material.
First, after seed layer 51 is deposited, base layer 52 is deposited, then first magnetic layer 53, then spacer layer 54, then second magnetic layer 55, and then optionally additional magnetic layers. A spacer / magnetic layer pair 56 is added and a protective coating 57 is applied in an optional last step.

Although the relative thickness of the layers is not believed to be critical to the practice of the present invention, the following ranges are provided as a guide. Preferably, the seed layer has a thickness of 10 to 50 nm. The role of the seed layer is [112] in the base layer.
PO and then [1010] P in the magnetic layer
Is to promote O. The base layer is typically thicker than the seed layer, but the base layer can vary in thickness (e.g.
Even with m), the magnetic properties of the disk change only slightly. A typical value for the thickness of the base layer is 50 nm. The ferromagnetic layers Mag1, Mag2, etc. can be 5 to 50 nm thick, typically 15 nm. The thicknesses of the magnetic layers need not be equal. The spacer layer is usually thinner than the base layer, typically 1-20 nm. Although the use, combination, and thickness of the coating are not critical to practicing the invention, typical thin film disks use coatings with a thickness of less than 15 nm.

FIG. 4A shows a single magnetic layer (NiAl / C
FIG. 4B shows a hysteresis loop of (r / CoPtCrTa), and FIG.
1 / Cr / CoPtCrTa / Cr / CoPtCrT
The loop of a) is shown. Unlike the prior art laminated disk shown in FIG. 3 (b), in which the hysteresis loop becomes irregular due to the two-mode switching, the laminated disk embodying the present invention (see FIG. 4 (b)) No mode switching effect is exhibited, and no anomalies occur in the hysteresis loop. This result indicates that NiAl
This is presumably because the deposition of the seed layer minimizes the loss of coercivity of the second layer due to the lower deposition temperature. To prove this, a single magnetic layer (N
The disk with iAl / Cr / CoPtCrTa) is heated to about 100 ° C. to correspond to (or exceed) the deposition temperature delta of the first and second magnetic layers of the laminated structure.
Only at two different temperatures. Over a wide range of Cr underlayer thicknesses, the Hc of the test disc was kept within about 100 Oe, indicating that Hc was not a strong function of the deposition temperature. Prior art laminated disks required a trade-off between increased SNR due to lamination and reduced coercive rectangle (S ^* ) and resolution. The laminated disk of the present invention minimizes these trade-offs by keeping the Hc of each magnetic layer closer and keeping S ^* higher. Another advantage is that the manufacture of the disk is easier due to its reduced susceptibility to temperature. That is, the possibility of being out of specification due to variations in the sputtering system is reduced.

NiAl, a preferred material for the seed layer
Forms a B2 (cesium chloride) structure while C forms
r has a bcc structure. The B2 structure is an ordered cubic structure that can be described as two interpenetrating simple cubic lattices with Al atoms occupying one lattice and Ni atoms occupying the other lattice. NiAl has about the same lattice constant as Cr, but NiAl tends to form smaller grain sizes due to the bonding of Ni and Al atoms, thereby reducing atomic mobility during deposition. Cobalt alloys used in magnetic recording are generally hexagonal closest packed (h
cp) having a predominant crystal structure. The cubic Cr underlayer can be deposited with PO [100] within normal thicknesses under standard sputtering conditions such as sufficiently high temperatures. This Cr [100] PO promotes PO [1120] in the Co alloy magnetic layer. This is often referred to as the desired PO for longitudinal recording. PO [1
120] results in a bicrystalline structure such that a plurality of [1120] particles having two orthogonal c-axis orientations are formed on a given Cr particle. (For example, Nolan
And Sinclair “Effects of Microst
ructural Features on Media Noise in Longitudinal R
ecording Media "(J. Appl. Phys., V73, p.5566, 199
3 years). Maintaining a high Hc in this orientation requires a high substrate temperature to cause sufficient separation (segregation) between the two crystals. Therefore, the Hc of the film having [1120] PO is extremely sensitive to temperature. Moreover, it is more difficult to maintain constant grain size and constant magnetic properties in the laminated [1120] PO film while maintaining interlayer epitaxy. Since the spacer layer Cr must grow on smaller crystals (two-crystal clusters) of the magnetic layer, the original Cr base layer particle structure cannot be reproduced. Therefore, [1120] PO is not desirable in a laminated magnetic medium. [112] PO can be induced in a Cr (or Cr alloy) base layer by depositing a seed layer such as NiAl. [1010] PO is epitaxially generated in the adjacent magnetic layer by the base layer having [112] PO. Next, a properly selected spacer layer can maintain a [1010] PO in each subsequent magnetic layer while maintaining a constant grain size throughout the structure.

The [1010] PO in the magnetic layer caused by the material structures described herein helps the favorable results observed for the laminated disk structures of the present invention, particularly to reduce the dependence of Hc on substrate temperature. It is thought that it has become. [1010] PO can be maintained in the second magnetic layer by appropriate selection and deposition of the spacer layer. The spacer layer material can be cubic with a lattice constant similar to PO [112] and Cr. Cr and Cr
Alloys are a convenient choice for the spacer layer for the same reasons as for the base layer. It is also possible to use a spacer having an hcp structure such that [1010] PO continues through the spacer layer. For example, ruthenium (R
u) and, by extension, the epitaxial matching of osmium (Os) and rhenium (Re), all of which have a hexagonal structure chosen as the spacer layer of the laminated disk. Further, for example, Cr> 35 atomic%
It is anticipated that alloys of hexagonal materials that maintain a hexagonal structure, such as the non-ferromagnetic CoCr alloy of U.S. Pat.

Laughlin et al. Suggest that the effect of a FeAl base layer on the magnetic properties of a magnetic layer deposited thereon is similar to that of NiAl (IEEE Trans.
Magnetic. 32 (5), September 1996, 3632.). Therefore, it is reasonable to suggest that FeAl also having the B2 structure can be used for the seed layer in the same manner as NiAl. Other non-B2 materials, such as NiCr, capable of inducing [112] PO in a Cr or Cr alloy base layer can also be used.

Although the above composition is shown without considering the percentage of foreign matter, it is understood by those skilled in the art that a thin film does not always contain foreign matter but contains some foreign matter. Is known to. Sputtering targets are typically specified at a purity of 99.9% or higher, but the purity of the film formed can be much lower due to foreign objects or other factors in the sputtering chamber. . For example, non-negligible amounts of oxygen and hydrogen can enter the film due to foreign matter due to air in the chamber. For certain carbon films, 5 atomic% hydrogen incorporation was measured in a typical sputtered layer. It is also known that small amounts of hydrogen are usually found in the Cr target and the resulting Cr layer. Also, small amounts of working gas, such as argon, in the sputtering system can be incorporated into the sputtered film. Contaminant amounts were not specifically measured in the disk samples described herein and were therefore assumed to be within the normal range for sputtered thin film disks as would be expected by one skilled in the art.

The thin-film disk made according to the present invention comprises:
It can be used to store data in a typical disk drive using a magnetoresistive or inductive head, and can be used with either a contact recording head or a flying head. The read / write head is arranged on a rotating disk in a standard manner to record or read magnetic information.

In summary, the following matters are disclosed regarding the configuration of the present invention.

(1) a substrate, a non-ferromagnetic seed layer deposited on the substrate, a non-ferromagnetic base layer deposited on the seed layer, [1010] a first ferromagnetic layer having directivity, A non-ferromagnetic spacer layer and a [1010] oriented second
Thin-film magnetic disk, comprising: a ferromagnetic layer; (2) The disk according to the above (1), wherein the base layer has [112] directivity. (3) The disk according to (1), wherein the spacer layer has [112] or [1010] directivity. (4) The disc according to (1), wherein the base layer has [112] directivity and the spacer layer has [112] or [1010] directivity. (5) The disk according to (1), wherein the seed layer contains a material having a B2 structure. (6) The disk according to (1), wherein the seed layer contains NiAl. (7) The disk according to the above (1), wherein the seed layer contains FeAl. (8) the spacer layer contains cobalt, chromium, ruthenium, osmium, or rhenium, and has a hexagonal structure;
The disc according to the above (1). (9) The coercivity of the first ferromagnetic layer and the second ferromagnetic layer is 10
The disc according to (1), wherein the disc differs by less than 0 Oe. (10) the seed layer includes NiAl, the base layer includes chromium or an alloy of chromium, the first ferromagnetic layer includes a cobalt alloy, the spacer layer includes chromium, ruthenium, osmium, rhenium, or an alloy thereof; The disk according to (1), wherein the second ferromagnetic layer comprises a cobalt alloy, and the disk further comprises a coating layer. (11) the thickness of the seed layer is between 2 nm and 50 nm, the thickness of the base layer is between 10 nm and 80 nm,
(10), wherein the thickness of the ferromagnetic layer is between 5 nm and 50 nm, and the thickness of the spacer layer is 1 to 20 nm.
Disc described in. (12) The cobalt alloy of the first and second ferromagnetic layers is C
oPtCrTa, CoPtCrB, or CoPtCr
The disk according to (10) above, (13) a motor for rotating the spindle, a non-ferromagnetic seed layer coupled to the spindle and deposited on the substrate,
Thin-film magnetic comprising a non-ferromagnetic underlayer deposited on a seed layer, a [1010] oriented first ferromagnetic layer, a non-ferromagnetic spacer layer, and a [1010] oriented second ferromagnetic layer. A disk drive that includes a disk and an actuator assembly that includes a head that writes magnetic information on the disk as it rotates. (14) The base layer has [112] directivity, the first ferromagnetic layer has [1010] directivity, and the spacer layer has [11] directivity.
(13) having the [2] or [1010] directivity
Disk drive as described in. (15) The disk drive according to (13), wherein the seed layer includes a material having a B2 structure. (16) The disk drive according to (13), wherein the seed layer contains NiAl. (17) The disk drive according to (13), wherein the seed layer contains FeAl. (18) The spacer layer is made of cobalt, chromium, ruthenium,
The disk drive according to the above (13), comprising osmium or rhenium and having a hexagonal structure. (19) The coercivity of the first ferromagnetic layer and the second ferromagnetic layer is 1
The disk according to (13), which differs by only 00 Oe.
drive. (20) the seed layer includes NiAl, the base layer includes chromium or an alloy of chromium, the first ferromagnetic layer includes a cobalt alloy, the spacer layer includes chromium, ruthenium, osmium, rhenium, or an alloy thereof; The disk drive according to (13), wherein the second ferromagnetic layer includes a cobalt alloy, and the magnetic disk further includes a cover layer. (21) The thickness of the seed layer is between 2 nm and 50 nm, the thickness of the base layer is between 10 nm and 80 nm,
(13), wherein the thickness of the ferromagnetic layer is between 5 nm and 50 nm, and the thickness of the spacer layer is 1 to 20 nm.
Disk drive as described in. (22) The cobalt alloy of the first and second ferromagnetic layers comprises:
CoPtCrTa, CoPtCrB, or CoPtC
r. The disk drive according to (21), wherein r is r. (23) a step of sputtering a seed layer on the substrate, a step of sputtering a base layer on the seed layer, a step of [1010] sputtering a first ferromagnetic layer having directivity on the base layer, Sputtering a spacer layer on the ferromagnetic layer; [10]
10] Sputtering a second ferromagnetic layer having directivity. (24) The method according to (23), wherein the seed layer is a material having a B2 structure. (25) The seed layer is NiAl, FeAl, or NiC
The method according to (23), wherein the material is r. (26) The method according to the above (23), wherein the seed layer is a material of NiAl, the base layer is Cr or a Cr alloy, and the first and second ferromagnetic layers are a cobalt alloy. (27) The above (2), wherein the base layer has a directivity of [112].
The method according to 3). (28) The method according to (23), wherein the spacer layer has a directivity of [112] or [1010].

[Brief description of the drawings]

FIG. 1 is a top view of a prior art disk drive with a rotary actuator useful in practicing the present invention.

FIG. 2 is a diagram showing a layer structure of a thin-film magnetic disk according to the present invention.

FIG. 3 (a) is a diagram showing a hysteresis loop of a thin-film magnetic disk of the prior art having a single magnetic layer,
FIG. 2B is a diagram showing a hysteresis loop of a conventional thin film magnetic disk having two laminated magnetic layers.

4A is a diagram showing a hysteresis loop of a thin-film magnetic disk having a NiAl seed layer and a single magnetic layer, and FIG. 4B is a diagram showing a thin-film magnetic disk having a NiAl seed layer and two laminated magnetic layers. FIG. 4 is a diagram showing a hysteresis loop of FIG.

FIG. 5 is a flowchart illustrating one method of making a disc according to the present invention.

[Explanation of symbols]

 Reference Signs List 11 substrate 12 seed layer 13 base layer 14 ferromagnetic layer 15 spacer layer 16 ferromagnetic layer 17 protective coating

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Mary Frances Dner United States 95062 Santa Cruz Forest Avenue 148, California 148 (72) Inventor Mohammad Taggie Mirza Marney United States 95120 San Jose, California Lodgewood Court 782

Claims (28)

[Claims] 1. A substrate, a non-ferromagnetic seed layer deposited on a substrate, a non-ferromagnetic base layer deposited on a seed layer, [1010] a first ferromagnetic layer having directivity, A ferromagnetic spacer layer, and [1010] a second ferromagnetic layer having directivity.
Thin-film magnetic disk. 2. The disk of claim 1 wherein the substrate has [112] orientation. 3. The method according to claim 1, wherein the spacer layer is [112] or [101].
0] The disk according to claim 1, which has directivity. 4. The disk of claim 1, wherein the base layer has [112] orientation and the spacer layer has [112] or [1010] orientation. 5. The seed layer includes a material having a B2 structure.
The disk according to claim 1. 6. The disk of claim 1, wherein the seed layer comprises NiAl. 7. The disk of claim 1, wherein the seed layer comprises FeAl. 8. The disk of claim 1, wherein the spacer layer comprises cobalt, chromium, ruthenium, osmium, or rhenium, and has a hexagonal structure. 9. The disk of claim 1, wherein the coercivity of the first ferromagnetic layer and the second ferromagnetic layer differ by less than 100 Oe. 10. The seed layer includes NiAl, the base layer includes chromium or an alloy of chromium, the first ferromagnetic layer includes a cobalt alloy, and the spacer layer includes chromium, ruthenium, osmium, rhenium, or an alloy thereof. The disk of claim 1, wherein the second ferromagnetic layer comprises a cobalt alloy and the disk further comprises a coating layer. 11. The method according to claim 11, wherein the thickness of the seed layer is between 2 nm and 50 nm, the thickness of the base layer is between 10 nm and 80 nm,
The thickness of the first ferromagnetic layer is between 5 nm and 50 nm,
The thickness of the spacer layer is 1 to 20 nm.
The disk according to item 0. 12. The method according to claim 1, wherein the cobalt alloy of the first and second ferromagnetic layers is CoPtCrTa, CoPtCrB, or CoPtCrB.
The disk of claim 10, which is tCr. 13. A motor for rotating a spindle, a non-ferromagnetic seed layer coupled to the spindle and deposited on a substrate, and a non-ferromagnetic base layer deposited on the seed layer.
[010] a thin-film magnetic disk including a first ferromagnetic layer having directivity, a non-ferromagnetic spacer layer, and a [1010] second ferromagnetic layer having directivity; An actuator assembly including a writing head;
drive. 14. The substrate according to claim 13, wherein the base layer has [112] orientation, the first ferromagnetic layer has [1010] orientation, and the spacer layer has [112] or [1010] orientation. Disk drive as described in. 15. The disk drive according to claim 13, wherein the seed layer comprises a material having a B2 structure. 16. The method of claim 13, wherein the seed layer comprises NiAl.
Disk drive as described in. 17. The method of claim 13, wherein the seed layer comprises FeAl.
Disk drive as described in. 18. The disk drive of claim 13, wherein the spacer layer comprises cobalt, chromium, ruthenium, osmium, or rhenium and has a hexagonal structure. 19. The disk drive according to claim 13, wherein the coercivity of the first ferromagnetic layer and the second ferromagnetic layer differ by 100 Oe. 20. A seed layer comprising NiAl, a base layer comprising chromium or an alloy of chromium, a first ferromagnetic layer comprising a cobalt alloy, and a spacer layer comprising chromium, ruthenium, osmium, rhenium or an alloy thereof. 14. The disk drive of claim 13, wherein the second ferromagnetic layer comprises a cobalt alloy and the magnetic disk further comprises a cover layer. 21. The seed layer thickness is between 2 nm and 50 nm, the base layer thickness is between 10 nm and 80 nm,
The thickness of the first ferromagnetic layer is between 5 nm and 50 nm,
The thickness of the spacer layer is 1 to 20 nm.
3. The disk drive according to 3. 22. The first and second ferromagnetic layers, wherein the cobalt alloy is CoPtCrTa, CoPtCrB, or CoPtCrB.
22. The disk drive according to claim 21, which is PtCr. 23. Sputtering a seed layer on a substrate, sputtering a base layer on the seed layer, [1010] sputtering a first ferromagnetic layer having directivity on the base layer, [1010] A method of manufacturing a thin-film disk, comprising: sputtering a spacer layer on one ferromagnetic layer; and [1010] sputtering a second ferromagnetic layer having directivity. 24. The method according to claim 23, wherein the seed layer is a material having a B2 structure. 25. The method of claim 23, wherein the seed layer is a material that is NiAl, FeAl, or NiCr. 26. A material wherein the seed layer is NiAl,
24. The method of claim 23, wherein the base layer is Cr or a Cr alloy and the first and second ferromagnetic layers are a cobalt alloy. 27. The method of claim 23, wherein the substrate has a [112] orientation. The spacer layer may be [112] or [101].
0].